connection string to local aspnetdb.mdf

This is connection string to your local database in visual studio

  <connectionStrings >
    <add name="MySqlConnection" providerName="System.Data.SqlClient" connectionString="data source=.SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true" />
  </connectionStrings>

Note that this .mdf file does not have a database inside. It is simply data inside the mdf file. Copy the above connection as it is in web.config file.